staple them up..or tape them up with duct tape
I'm over the whole matting and mounting and framing thing.. talk abount money down the drain
staple them up hap-hazzardly - make it a style!
For an industrial look, get pieces of galvanized sheet metal and attach the prints to those with magnets. Reusable.
Mike → "Junior Liberatory Scientist" ✌
Tenter hooks holding glass to wall with matted print behind is another option, but I think by the time you have the glass and mat you're pretty close to price of a simple black frame. We attended a show a couple of years ago in which one of the photographers put his work in homemade frames made from scrap wood. Very nice presentation. His stuff was pretty big too, like maybe 40" square or so.
The cheapest way would be to dry mount them to foam core and then use Swiss Clips without an over mat. Leaving off the over mat would keep the weight down too. Foam core is pretty inexpensive. It would probably be best to trim off any paper around the image before you mount it. You might want to consider using a color besides white for the foam core as well.
I would try Ikea first.reasonably priced frames, wide choice of sizes, and styles.
get them box mounted at printmount.
they work with large pieces and small
and their prices are very reasonable.
Matte the prints, cut a sheet of clear glass to the size of the matte then use tenterhooks, pounded directly into the wall to support the "sandwich" on all four corners.
Assuming your gallery's walls are covered in homasote or cork board.
Tenterhooks (AKA: "L-pins") are cheap. 10¢ apiece from this site: http://www.kilianhardware.com/tenterhooks.html
In girum imus nocte et consumimur igni.
Personally I think some people overvalue their work, and their framing reflects their insecurity.
Anyone can buy a nice frame. Few take pictures that I care about.
Put another way: I'd rather see a Sudek print thumbtacked to a wall than a Ken Rockwell in an archival frame.